Gentle Flyer, Thanks for asking.
As with most things Governmental the vital information is contained in amongst a lot of stuff you don't want but try this:
Start here with the US FAA Airman's Information Manual (AIM):
https://www.faa.gov/air_traffic/publ...section_2.html
Noting that to an IFR aircraft; Class E airspace is Controlled Airspace, radio required, clearance required.
To a VFR aircraft, Class E airspace is NOT Controlled Airspace - radio is not required and no clearance is required.
But if VFR and you have a radio you can have traffic information limited only by controller workload.
There are some superb graphics and short form explanations in the PIlots Handbook of Aeronautical Knowledge (PHAK)
at:
https://www.faa.gov/regulations_poli..._phak_ch15.pdf
Please note that I want to see the US system of airspace classification and procedures for separation of aircraft in IMC (not those who have planned IFR but those in IMC)
Done as it is done in the USA without any "Australianisation" of the very well proven USA system - we muck it up every time we try that.
The US system allows the maximum possible use of airspace by VFR aircraft and there are many organisations such as US AOPA and EAA who work with the FAA to ensure this remains.
(Can you imagine trying to run an Oshkosh Convention here with more aircraft on one US airport than we have in the whole country??)